Interactions of cyclodextrins and their derivatives with toxic organophosphorus compounds

• Sophie Letort,
• Sébastien Balieu,
• William Erb,
• Géraldine Gouhier and
• François Estour

Beilstein J. Org. Chem. 2016, 12, 204–228, doi:10.3762/bjoc.12.23

• technics [43]. Despite the pronounced solubility changes consistent with complex formation, little variations in the UV spectra, combined with the guest’s small chemical shifts observed in 1H NMR experiments (0.01–0.06 ppm), suggest the formation of external complexes rather than an inclusion complex

• . However the inclusion complex formation was strengthen by molecular modeling studies with the aromatic group included into the cavity. Finally, DSC curves showed a first endothermic portion starting at 225 °C, typical of a melting process, and a second sharp exothermic decomposition peak, proving the

• binding constant values and the hydrophobicity of the pesticides, suggesting that steric effects are probably predominantly involved in complex formation. The inclusion of the apolar heterocyclic ring into the CD cavity is the most likely situation to occur. γ-CD has the largest secondary alcohols rim

Supramolecular structures based on regioisomers of cinnamyl-α-cyclodextrins – new media for capillary separation techniques

• Gabor Benkovics,
• Ondrej Hodek,
• Martina Havlikova,
• Zuzana Bosakova,
• Pavel Coufal,
• Milo Malanga,
• Eva Fenyvesi,
• Andras Darcsi,
• Szabolcs Beni and
• Jindrich Jindrich

Beilstein J. Org. Chem. 2016, 12, 97–109, doi:10.3762/bjoc.12.11

• that the position of the cinnamyl group plays an important role in the intermolecular complex formation. Keywords: capillary electrophoresis; cyclodextrin derivatives; mono-cinnamyl; regioisomers; supramolecular structures; Introduction Supramolecular polymers (SP) are aggregates of monomer units

• requirement for the effective SP formation. In the case of 6-O-monobenzoyl-β-CD, for example, the direct attachment of the phenyl moiety to the CD rim did not result in intermolecular complex formation [6]. On the other hand too long and flexible spacers between the host and the guest moiety favored the self

• that the cavity of the CD shows distinguishable inclusion affinities towards different substrates, even to homologues and isomers. A self-sorting complex formation ability was described for the two regioisomers of monocinnamoyl-α-CD (Cio-α-CD) [9]. While the 2-Cio-α-CD isomer formed an insoluble double

Determination of formation constants and structural characterization of cyclodextrin inclusion complexes with two phenolic isomers: carvacrol and thymol

• Miriana Kfoury,
• David Landy,
• Steven Ruellan,
• Lizette Auezova,
• Hélène Greige-Gerges and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2016, 12, 29–42, doi:10.3762/bjoc.12.5

• Phase solubility studies are widely used to evaluate the ability of CDs to increase the aqueous solubility of the guests. They also lead to the determination of diverse parameters involved in complex formation such as Kf value, complexation efficiency (CE), optimal molar ratio for solid inclusion

• lipophilic cavity. This supported the fact that hydrophobic forces play a leading role in inclusion complex formation. Although ΔE values clearly illustrate the stability of each inclusion complex, it has to be underlined that such theoretical energies cannot be directly compared to Kf values, as the

Physical properties and biological activities of hesperetin and naringenin in complex with methylated β-cyclodextrin

• Waratchada Sangpheak,
• Jintawee Kicuntod,
• Roswitha Schuster,
• Thanyada Rungrotmongkol,
• Peter Wolschann,
• Nawee Kungwan,
• Helmut Viernstein,
• Monika Mueller and
• Piamsook Pongsawasdi

Beilstein J. Org. Chem. 2015, 11, 2763–2773, doi:10.3762/bjoc.11.297

• β-CD at different temperatures in the range of 15–45 °C [42]. The temperature parameter contributes to the strength of the interaction between the host and guest molecules in complex formation. Size matching of the host and guest molecules also dominates complex stability. Our results showed that

• flavanones and their complexes. (A) hesperetin and (B) naringenin. Complex formation was by freeze-drying. The influence of flavanones and their complexes on IL-6 secretion from LPS-stimulated macrophages. Cytotoxicity of free flavanones and their inclusion complexes on different cancer cell lines. The

Inclusion complexes of 2-methoxyestradiol with dimethylated and permethylated β-cyclodextrins: models for cyclodextrin–steroid interaction

• Mino R. Caira,
• Susan A. Bourne,
• Halima Samsodien and
• Vincent J. Smith

Beilstein J. Org. Chem. 2015, 11, 2616–2630, doi:10.3762/bjoc.11.281

• complex formation between 2ME and both of the host molecules was finally confirmed by comparing the FTIR spectrum of pure 2ME with those of the pure CD and the putative CD-2ME inclusion complexes prepared by kneading; characteristic bands for 2ME (at 1600, 2861, 2903, 3179 and 3413 cm−1) were seen to

• consistent with inclusion complex formation. A PXRD trace of the material did not match any of those generated for known polymorphs of the pure host DIMEB [16], again supporting the formation of an inclusion complex between DIMEB and 2ME. As for the characterization of the β-CD·2ME complex described above

• illustrate for the first time details of the encapsulation of a ‘classical’ steroidal molecule by cyclodextrin hosts. In addition, from the variety of host and guest conformations observed in the TRIMEB·2ME complex, even in one crystal, it is evident that complex formation involves some degree of ‘mutually

Co-solvation effect on the binding mode of the α-mangostin/β-cyclodextrin inclusion complex

• Chompoonut Rungnim,
• Sarunya Phunpee,
• Manaschai Kunaseth,
• Supawadee Namuangruk,
• Kanin Rungsardthong,
• Thanyada Rungrotmongkol and
• Uracha Ruktanonchai

Beilstein J. Org. Chem. 2015, 11, 2306–2317, doi:10.3762/bjoc.11.251

• in such studies may result in ternary (host:guest:co-solvent) complex formation. The objective of this work was to investigate the effect of ethanol as a co-solvent on the inclusion complex formation between α-mangostin (α-MGS) and β-CD, using both experimental and theoretical studies. Experimental

• phase-solubility studies were carried out in order to assess complex formation, with the mechanism of association being probed using a mathematical model. It was found that α-MGS was poorly soluble at low ethanol concentrations (0–10% v/v), but higher concentrations (10–40% v/v) resulted in better α-MGS

• -solvent on the complex formation between α-mangostin (α-MGS) and β-CD. Phase solubility studies were carried out in order to assess the formation of those complexes at various β-CD concentrations, with ethanol as a co-solvent. A simple mathematical model was then applied to explain the solubility of α-MGS

Cholesterol lowering effects of mono-lactose-appended β-cyclodextrin in Niemann–Pick type C disease-like HepG2 cells

• Keiichi Motoyama,
• Yumi Hirai,
• Rena Nishiyama,
• Yuki Maeda,
• Taishi Higashi,
• Yoichi Ishitsuka,
• Yuki Kondo,
• Tetsumi Irie,
• Takumi Era and
• Hidetoshi Arima

Beilstein J. Org. Chem. 2015, 11, 2079–2086, doi:10.3762/bjoc.11.224

• , etc., through complex formation [5][6]. Recently, 2-hydroxypropyl-β-cyclodextrin (HP-β-CyD) has attracted considerable attention for the treatment of NPC disease [4][7][8][9]. The administration of HP-β-CyD to NPC1-knock out (Npc1−/−) mice has been reported to remarkably prolong the life span of the

• adamantane, which is often used as a guest molecule for β-CyD, using the quartz crystal microbalance method (QCM) in phosphate-buffered saline (PBS, pH 7.4) at 37 °C. As a result, the dissociation constant of Lac-β-CyD with adamantane was 9.8 × 10−7 M due to the potent complex formation. Therefore, this

Consequences of the electronic tuning of latent ruthenium-based olefin metathesis catalysts on their reactivity

• Karolina Żukowska,
• Eva Pump,
• Aleksandra E. Pazio,
• Krzysztof Woźniak,
• Luigi Cavallo and
• Christian Slugovc

Beilstein J. Org. Chem. 2015, 11, 1458–1468, doi:10.3762/bjoc.11.158

• conducted by BP86//SVP, solvent effects were added by single point calculations using M06//TZVP functional (cf. Supporting Information File 1). The first question tackled concerned the anticipated coordination of the carbonyl group in compound 15 to form the corresponding 18-electron complex. Formation of

Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F₄TCNQ

• Raúl García,
• M. Ángeles Herranz,
• Edmund Leary,
• M. Teresa González,
• Gabino Rubio Bollinger,
• Marius Bürkle,
• Linda A. Zotti,
• Yoshihiro Asai,
• Fabian Pauly,
• Juan Carlos Cuevas,
• Nicolás Agraït and
• Nazario Martín

Beilstein J. Org. Chem. 2015, 11, 1068–1078, doi:10.3762/bjoc.11.120

• , suggesting no complexation. The solvent was then changed to acetonitrile, a more polar solvent better able to stabilize complex formation, but this too did not give the anticipated strong color change. Only when the solution was heated at reflux for 3 h under ambient conditions and a large excess of TCNQ was

Terminal lipophilization of a unique DNA dodecamer by various nucleolipid headgroups: Their incorporation into artificial lipid bilayers and hydrodynamic properties

• Emma Werz and
• Helmut Rosemeyer

Beilstein J. Org. Chem. 2015, 11, 913–929, doi:10.3762/bjoc.11.103

• , equimolar amounts of complementary and non-complementary DNA strands as well as a SYBR Green I solution were added to the bilayer-bound lipo-oligonucleotide. The kinetics of the ternary complex formation at the bilayer surface as well as the stability of the complexes against perfusion was measured by

Multivalent dendritic polyglycerolamine with arginine and histidine end groups for efficient siRNA transfection

• Fatemeh Sheikhi Mehrabadi,
• Hanxiang Zeng,
• Mark Johnson,
• Cathleen Schlesener,
• Zhibin Guan and
• Rainer Haag

Beilstein J. Org. Chem. 2015, 11, 763–772, doi:10.3762/bjoc.11.86

• at N/P ratios between 2 to 4. The binding capacity of all vectors was slightly different from each other. The results of this assay clearly display that all synthesized vectors were able to form polyplexes with siRNA at low N/P ratios. Moreover, the complex formation ability of the new vectors is

Discrete multiporphyrin pseudorotaxane assemblies from di- and tetravalent porphyrin building blocks

• Mirko Lohse,
• Larissa K. S. von Krbek,
• Sebastian Radunz,
• Suresh Moorthy,
• Christoph A. Schalley and
• Stefan Hecht

Beilstein J. Org. Chem. 2015, 11, 748–762, doi:10.3762/bjoc.11.85

• only contributes to binding enhancement, but also helps to exert control over complex formation. For example, “molecular elevators” have been constructed by Stoddart et al. [30][31] and giant porphyrin wheels were prepared by Anderson and co-workers [32][33], both using a multivalent template strategy

Probing multivalency in ligand–receptor-mediated adhesion of soft, biomimetic interfaces

• Stephan Schmidt,
• Hanqing Wang,
• Daniel Pussak,
• Simone Mosca and
• Laura Hartmann

Beilstein J. Org. Chem. 2015, 11, 720–729, doi:10.3762/bjoc.11.82

• protein receptors are formed to control cell–cell recognition, cell adhesion and related processes. The aim of this work is to shed light on the principles of complex formation between surface anchored carbohydrates and receptor surfaces by measuring the specific adhesion between surface bound mannose on

• generally low affinity between sugars and receptors and possibly also by the high flexibility of the polymeric mannose linkers [9]. High molecular flexibility causes a high degree of conformational entropy that negatively affects complex formation between ligands and receptors [23]. Also the design of the

Exploring monovalent and multivalent peptides for the inhibition of FBP21-tWW

• Lisa Maria Henning,
• Sumati Bhatia,
• Miriam Bertazzon,
• Michaela Marczynke,
• Oliver Seitz,
• Rudolf Volkmer,
• Rainer Haag and
• Christian Freund

Beilstein J. Org. Chem. 2015, 11, 701–706, doi:10.3762/bjoc.11.80

• by the individual WW domains [5]. At position P4 proline can be replaced by leucine, a residue well compatible with the PPII helical conformation. Arginine is preferred at position 6 or 9, highlighting the importance of a positive charge in complex formation. Interestingly, WW1 tolerates an exchange

Fluoride-driven ‘turn on’ ESPT in the binding with a novel benzimidazole-based sensor

• Kai Liu,
• Xiaojun Zhao,
• Qingxiang Liu,
• Jianzhong Huo,
• Bolin Zhu and
• Shihua Diao

Beilstein J. Org. Chem. 2015, 11, 563–567, doi:10.3762/bjoc.11.61

• changes with two well-defined isosbestic points (344, 270 nm) indicated the formation of a single complex between BIP and fluoride [2]. Evidence for 1:1 complex formation was also validated by non-linear least-square analysis [31] for BIP with F−. The association constant, calculated from the UV−vis plot

Synthesis and surface grafting of a β-cyclodextrin dimer facilitating cooperative inclusion of 2,6-ANS

• Lars W. Städe,
• Thorbjørn T. Nielsen,
• Laurent Duroux,
• Reinhard Wimmer,
• Kyoko Shimizu and
• Kim L. Larsen

Beilstein J. Org. Chem. 2015, 11, 514–523, doi:10.3762/bjoc.11.58

• accessibility for inclusion-complex formation [13]. The research presented here aims to bring the cooperative effects of β-CD dimers to solid silicon dioxide surfaces. Modification of these surfaces allows the introduction of the extraordinary binding affinity and selectivity of CD dimers to silicon wafer

• grafting onto azide-functionalized quartz surfaces. Host–guest interactions with the fluorescent guest molecule 2-anilinonaphthalene-6-sulfonic acid (2,6-ANS) were investigated by NMR and fluorescence spectroscopy. Further, we probe the complex formation of the surface-grafted β-CD dimer with 2,6-ANS by

• to 450 nm and 435 nm for the 2,6-ANS solutions with parent β-CD and the β-CD dimer, respectively. These observations lead to the conclusion that 2,6-ANS experiences a more non-polar environment upon inclusion complex formation with the β-CD dimer. For the inclusion of parent β-CD, it has been

Formation of nanoparticles by cooperative inclusion between (S)-camptothecin-modified dextrans and β-cyclodextrin polymers

• Thorbjørn Terndrup Nielsen,
• Catherine Amiel,
• Laurent Duroux,
• Kim Lambertsen Larsen,
• Lars Wagner Städe,
• Reinhard Wimmer and
• Véronique Wintgens

Beilstein J. Org. Chem. 2015, 11, 147–154, doi:10.3762/bjoc.11.14

• thermodynamic parameters derived assuming a 1:1 complex formation between β-CD and CPT units are given in Table 2. The interactions between the polymers were in both cases exothermic. The apparent association constant (Ka) is more than one order of magnitude higher for D70GP-CPT2 than D10GP-CPT1. The complex

• formation is enthalpy driven in the case of D10GP-CPT1, but mainly entropy driven (|TΔS| > |ΔH|) in the case of D70GP-CPT2. This high positive entropy variation shows a cooperative inclusion of the polymers. No binding between native β-CD and D70GP-CPT2 could be measured by ITC. Figure 1 shows the heat flow

Inclusion of trans-resveratrol in methylated cyclodextrins: synthesis and solid-state structures

• Lee Trollope,
• Dyanne L. Cruickshank,
• Terence Noonan,
• Susan A. Bourne,
• Milena Sorrenti,
• Laura Catenacci and
• Mino R. Caira

Beilstein J. Org. Chem. 2014, 10, 3136–3151, doi:10.3762/bjoc.10.331

• derivatised) to establish their effect on the aqueous solubility of trans-resveratrol and to estimate association constants for complex formation. Keywords: cyclodextrin; inclusion complexes; thermal analysis; trans-resveratrol; X-ray structures; Introduction The naturally occurring phytoalexin trans

• complexation. It should be noted that, in general, solid-state characterization using the latter techniques is limited, the evidence for genuine inclusion complex formation not always being definitive because the preparative method may result in one or both components becoming amorphous, or an unexpected solid

• thermoanalytical methods could be interpreted on a sound basis. Since a primary application of CDs is enhancement of the solubility of poorly soluble guest molecules [6], phase solubility studies [11] were conducted, and the results, including estimates of complex formation constants, are also reported here

Release of β-galactosidase from poloxamine/α-cyclodextrin hydrogels

• César A. Estévez,
• José Ramón Isasi,
• Eneko Larrañeta and
• Itziar Vélaz

Beilstein J. Org. Chem. 2014, 10, 3127–3135, doi:10.3762/bjoc.10.330

• aim is to determine the effectiveness of self-assembled, α-cyclodextrin/90R4 poloxamine gels and tablets for the controlled release of β-galactosidase at different pH values. Results and Discussion Complex formation between lactase, α-CD and 90R4 The supramolecular complex formation between the

Synthetic strategies for the fluorescent labeling of epichlorohydrin-branched cyclodextrin polymers

• Milo Malanga,
• Mihály Bálint,
• István Puskás,
• Kata Tuza,
• Tamás Sohajda,
• László Jicsinszky,
• Lajos Szente and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2014, 10, 3007–3018, doi:10.3762/bjoc.10.319

• polymeric network before the introduction of the anchoring group for the fluorescent labeling (Scheme 3). Methylated cyclodextrins have peculiar properties concerning both solubility and complex formation thus targeting a water-soluble methylated β-CD polymer with a low degree of substitution can be

A comparative study of the interactions of cationic hetarenes with quadruplex-DNA forming oligonucleotide sequences of the insulin-linked polymorphic region (ILPR)

• Darinka Dzubiel,
• Heiko Ihmels,
• Mohamed M. A. Mahmoud and
• Laura Thomas

Beilstein J. Org. Chem. 2014, 10, 2963–2974, doi:10.3762/bjoc.10.314

• derivative 4 with the ILPR-DNA. However, it should be noted that strong fluctuations in the Job plot of the complex formation between ligand 1e and ILPR-DNA a2, especially between XLigand = 0–0.4, indicate strong heterogeneous binding under these conditions. CD spectroscopic analysis of ligand–DNA

• structure of a2 [9][10] the induced increase may indicate a stabilization of this DNA structure upon complex formation. Moreover, a comparison with the telomeric quadruplex 22AG shows that the ligands 1d, 1e and 6 induce the same effect on the CD band of this quadruplex at 295 nm (Supporting Information

• complex formation between a2 and 1d and 1e does not lead to a significant change of the DNA structure. In the case of ligands 2, 4, 5 and 6, a negative CD band developed at 265 nm together with a weak positive band with a maximum at ca. 240 nm upon association with quadruplex a2 (Figure 8). Along with the

Synthesis and characterization of a new photoinduced switchable β-cyclodextrin dimer

• Florian Hamon,
• Claire Blaszkiewicz,
• Marie Buchotte,
• Estelle Banaszak-Léonard,
• Hervé Bricout,
• Sébastien Tilloy,
• Eric Monflier,
• Christine Cézard,
• Laurent Bouteiller,
• Christophe Len and
• Florence Djedaini-Pilard

Beilstein J. Org. Chem. 2014, 10, 2874–2885, doi:10.3762/bjoc.10.304

• complex formation through their wider rim with two adamantyl units belonging to two different ADAdim 4 molecules, leading to the formation of supramolecular polymers with an n:n stoichiometry. This situation has already been encountered in the complex of ADAdim 4 and a β-CD dimer bearing a terephthalic

Synthesis of modified cyclic and acyclic dextrins and comparison of their complexation ability

• Kata Tuza,
• László Jicsinszky,
• Tamás Sohajda,
• István Puskás and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2014, 10, 2836–2843, doi:10.3762/bjoc.10.301

• from the three native α-, β-, and γ-cyclodextrins, respectively, are also suitable complexing agents. These maltooligomers are often considered as linear dextrins unable to form inclusion complexes [4]. Komiyama et al. found that there is complex formation but the complex forming ability of closed ring

• favorably cyclic conformation and this explains the weak complex formation contrary to the smaller-sized non-cyclic analogs (G3, G4 and G5) not showing any interaction. In another study of Bettinetti et al. G7 was found to wrap up naproxen, taking on a cyclic conformation and forming a ‘pseudo’ inclusion

A study on the inhibitory mechanism for cholesterol absorption by α-cyclodextrin administration

• Takahiro Furune,
• Naoko Ikuta,
• Yoshiyuki Ishida,
• Hinako Okamoto,
• Daisuke Nakata,
• Keiji Terao and
• Norihiro Sakamoto

Beilstein J. Org. Chem. 2014, 10, 2827–2835, doi:10.3762/bjoc.10.300

• solubility of cholesterol in the lumen of the small intestine via the precipitation of lecithin from bile salt micelles by complex formation with α-CD. It further indicates that the lecithin precipitation effect on the bile salt micelles by α-CD addition clearly differs from addition of other water-soluble

Thermal and oxidative stability of the Ocimum basilicum L. essential oil/β-cyclodextrin supramolecular system

• Daniel I. Hădărugă,
• Nicoleta G. Hădărugă,
• Corina I. Costescu,
• Ioan David and
• Alexandra T. Gruia

Beilstein J. Org. Chem. 2014, 10, 2809–2820, doi:10.3762/bjoc.10.298

• complexation process, was 74.2%. This relatively high recovery yield for the β-CD complex can be explained by the lower water (as well as ethanol/water) solubility. The quality of the essential oil/β-CD complex formation was sustained by the morphology of the complex crystals, evaluated by scanning electron

• ][42][43][44][45]. The main compounds from O. basilicum L. essential oil, linalool and methylchavicol, have been used as guests for bicomponent encapsulation in CDs [39][41][46][47]. Linalool was encapsulated in β-CD [41] and its derivative 2-hydroxypropyl-β-CD [39] with good results and the complex

• formation was determined by thermal analysis (TG, DSC), FTIR and XRD. The quality of the encapsulation has been studied by gas chromatographic methods. Methylchavicol and other structurally related volatiles were also encapsulated in various natural CDs such as α- and β-CD, as well as in semisynthetic